feat(core): also sync values which are not versions

## Description

It would be helpful to have the capability to synchronize more fields than just dependencies or to specify values for certain fields.

For example, in a mono-repo, I want to maintain consistency in the author field. Ideally, updating this field once should automatically sync the change across all packages.

Another use case could involve ensuring that every package.json includes a defined set of scripts, with the desired outcome being that these specific scripts are synchronized, while any additional scripts in each file remain unaffected.

## Suggested Solution

One potential approach to address this could be implemented in the .syncpackrc file:

```json
{
"templateFields": [
"author": "Cool Dev Person ",
"scripts": [
"build": "tsc",
"do:something": "something --makeItCool"
]
],
}
```

Start with the proposed .syncpackrc templateFields configuration and inspect how package.json values are currently synchronized. Define how author and selected scripts should propagate across packages while leaving additional scripts unchanged. Done means the requested fields can be synchronized without affecting unrelated package.json values.

Written by the indexing model from the issue text.